1. Technical Field
The present disclosure relates to a non-contact type tonometer.
2. Related Art
A non-contact type tonometer measures the eye pressure of an examinee's eye in a non-contact manner. Specifically, the non-contact type tonometer first sprays a liquid onto the cornea of the examinee's eye via a nozzle. The non-contact type tonometer then optically detects a deformed state of the cornea upon the spraying of liquid. In this way, the non-contact type tonometer measures the eye pressure of the examinee's eye based on the deformed state of the cornea in a non-contact manner. A known example of such a non-contact type tonometer is an apparatus including an optical system for measuring the corneal thickness of the examinee's eye. The apparatus corrects the eye pressure value of the examinee's eye based on an obtained measurement result (see, for example, JP-A-8-507463).
An apparatus described in JP-A-2002-102170 causes a light flux to obliquely enter the examinee's eye during measurement of the corneal thickness. Reflected light from the cornea is received by a light receiving device, such as a line sensor. The apparatus measures the corneal thickness based on a peak value of a light receiving signal for reflected light from front and rear surfaces of the cornea. In the apparatus, alignment in an actuation distance direction is conducted with reference to the peak value of the light receiving signal for the reflected light from the corneal front surface, during both eye pressure measurement and corneal thickness measurement.